1. Field of the Invention
The present invention relates to an outboard engine system comprising a casing including a driving-force transmitting means provided therein, an engine for transmitting power to a propeller through the driving-force transmitting means, the casing and the engine being carried on a hull for tilting-up movement, an engine cover made of a synthetic resin and covering at least an upper portion of the engine, and an undercover including a pair of cover halves made of a synthetic resin and connected to each other to cover at least a lower portion of the engine from opposite sides, the undercover being detachably connected at an upper end thereof to a lower end of the engine cover and fixed to an upper portion of the casing.
2. Description of the Related Art
Such an outboard engine system is conventionally known from Japanese Patent No. 2704762 and the like, for example, and an outboard engine system of a construction having a grip portion provided at an upper portion of an engine cover for conducting a tilting-up operation is also already known from Japanese Utility Model Application Laid-open No.59-75398, for example.
In the known systems, the engine cover and the undercover detachably connected to each other are merely supported on the casing by fixing of the undercover to the upper portion of the casing. When an operator grasps the grip portion of the engine cover to conduct the tilting-up operation, the lower portion of the engine cover and the upper portion of the undercover are deformed somewhat and hence, in some cases, the operator may feel the impression of softness and weakness of the engine cover and the undercover as if they are short in rigidity and as a result, there is a possibility that the impression of a high grade might be impeded.
The present invention is accomplished in view of the above circumstances, and it is an object of the present invention to provide an outboard engine system, wherein the impression of rigidity of the engine cover and the undercover can be obtained during the tilting-up operation.
To achieve the above object, according to a first aspect and feature of the present invention, there is provided an outboard engine system comprising a casing including a driving-force transmitting means provided therein, an engine mounted at an upper end of the casing for transmitting power through the driving-force transmitting means to a propeller carried at a lower end of the casing, the casing and the engine being carried on a hull for tilting-up movement about an axis of a horizontal pivot, an engine cover made of a synthetic resin, which covers at least an upper portion of the engine and is provided at an upper portion thereof with a tilting-up grip portion, and an undercover comprising a pair of cover halves made of a synthetic resin and connected to each other to cover at least a lower portion of the engine from opposite sides, the undercover being detachably connected at an upper end thereof to a lower end of the engine cover and fixed to an upper portion of the casing, wherein the undercover is detachably fixed at the upper portion thereof to an engine body of the engine.
With the arrangement of the first feature, the undercover is detachably fixed at the upper portion thereof to an engine body of the engine. Therefore, the upper portion of the undercover is firmly supported on the engine body, and the lower portion of the engine cover is firmly supported on the engine body through the upper portion of the undercover. Thus, when an operator has grasped the grip portion of the engine cover to conduct the tilting-up operation, the deformation of the lower portion of the engine cover and the upper portion of the undercover can be suppressed to a small level, thereby providing the impression of rigidity of the engine cover and the upper portion.
According to a second aspect and feature of the present invention, in addition to the first feature, the engine, which is a 4-cycle engine with at least an upper half thereof being covered with the engine cover, includes an engine block in which a vertically extending crankshaft is rotatably carried, a cylinder head coupled to the engine block, a head cover coupled to the cylinder head to define a valve operating chamber between the head cover and the cylinder head, a valve operating mechanism accommodated in the valve operating chamber and including a camshaft having an axis parallel to the crankshaft, a belt transmitting means which connects the camshaft and the crankshaft to each other and includes a driven pulley fixed to one end of the camshaft above the cylinder head and a timing belt wound around the driven pulley, and a belt cover which covers at least a portion of the belt corresponding to the driven pulley, and the outboard engine system further includes a breather pipe which extends along an outer surface of the belt cover and is fixed at an intermediate portion thereof to the belt cover, the breather pipe being connected at one end to an upper portion of the head cover to lead to a breather chamber defined in the head cover, and at the other end to an intake device disposed on one side of the engine block and connected to the cylinder head.
With the arrangement of the second feature, the breather pipe is mounted on the side of the intake device disposed on one side of the engine block to extend along the outer surface of the belt cover disposed above the cylinder head. Moreover, the breather pipe is connected at one end thereof to the upper portion of the head cover and fixed at the intermediate portion thereof to the belt cover. Therefore, the breather pipe can be disposed in proximity to the belt cover to such an extent that it is in contact with the belt cover, but cannot overhang sideways from the intake device. Even if the engine cover is relatively small, the breather pipe can be disposed compactly within the engine cover.